Observe the diagram. Which of these would NOT increase calcium levels in the blood? A) Osteoclast activity is inhibited. B) The kidneys reabsorb calcium from urine. C) Osteoclasts release calcium from the bones. D) Calcium absorption increases in the small intestines via Vitamin D synthesis.

Which class of organic compounds makes up the channels and pumps that move materials from one side of the cell membrane to the other? a.) carbohydrates b.) lipids c.) proteins d.) nucleic acids

Hey me with this one❤☺❤ how do you say that a cell also has a life span and death like an organism? give one example.

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.